It is worth noting that having ALMA high-frequency observations that sample the peak of the dust emission (or even beyond the peak) is critical for robust constraints on the dust temperature (and hence, luminosity). But even with multi-band observations, potential degeneracies with the dust emissivity index and dust opacity assumptions need to be taken into account (e.g., [1]}, [2]}, [3]}). For example, in a detailed study of the dust emission of SMGs, [1]} show that with only three ALMA bands sampling the dust emission SED, it is very difficult to distinguish between optically thin dust emission and dust that it optically thick at far-infrared wavelengths – but important systematics can be introduced in the derived dust temperatures and masses (Fig. REF ).
